Personally I believe this version of events from wiki, it was a simple case of the other 3 not wanting Pete in the band anymore, very hard on Pete but thats life.........I feel very sorry for him.
Martin and his engineers wanted to use an experienced session drummer in Best's place, as was common practice amongst producers. Many years later Martin still expressed regret about this decision and what followed: "I decided that the drums, which are really the backbone of a good rock group, didn't give the boys enough support. They needed a good solid beat and I said to Brian, 'Look, it doesn't matter what you do with the boys, but on record, nobody need know. I'm gonna use a hot drummer.' Brian [Epstein] said, 'Okay, fine.' I felt guilty because I felt maybe I was the catalyst that had changed his [Best's] life".
When the group heard that Martin and the engineers preferred a session drummer for their upcoming recording session, Lennon, McCartney, and Harrison asked Epstein to dismiss Best from the band. Before Epstein became The Beatles' manager, Best's mother had arranged all the bookings in Liverpool, after they had parted company with Williams.
Epstein agonised about the decision. As he wrote in his autobiography, A Cellarful of Noise, he "wasn't sure" about Martin's assessment of Best's drumming and "was not anxious to change the membership of The Beatles at a time when they were developing as personalities ... I asked The Beatles to leave the group as it was." Epstein also asked Bob Wooler for advice, to which Wooler replied that it was not a good idea, as Best was too popular with the fans. Ultimately, Epstein decided that "if the group was to remain happy Pete Best must go". He summoned Best to his office and dismissed him on 16 August 1962, two years and four days after Best had first joined the group.
Best's friend, Neil Aspinall, was waiting for him downstairs in Epstein's NEMS record shop after the meeting. The two went to The Grapes pub, across from The Cavern Club, where The Beatles had often played. Starting in 1961, Aspinall had become good friends with Best and subsequently rented a room in the house where Best lived with his parents. Best had asked Aspinall to become the band's roadie, resulting in Aspinall buying an old Commer van for 80 pounds. He had been employed as the band's road manager and personal assistant, but was furious at the news, saying that he would stop working for them as well, but Best strongly advised him to remain with the group. Aspinall asked Lennon at the next concert why they had fired Best, to which he replied, "It's got nothing to do with you, you're only the driver."
Prior to Best's dismissal, during one of the extended business trips of Best's father, the 19-year-old Aspinall became romantically involved with Best's mother, Mona Best, who was 17 years his senior. During this period, he fathered a child by Mona: Vincent "Roag" Best. Roag Best was born in late July 1962, just three weeks prior to Best's dismissal. Despite his initial support after Best's dismissal, Aspinall elected to stay in the employ of the group, and ended his relationship with Mona (and their three-week-old baby, Roag).
Mersey Beat magazine editor, Bill Harry, has claimed that the vacant drummer position in The Beatles was initially offered by Epstein to Johnny Hutchinson of The Big Three, whom he also managed. Hutchinson turned down the job, saying, "Pete Best is a very good friend of mine. I couldn't do the dirty on him", although he did agree to play three bookings until Starr could join. Starr had previously played with Rory Storm and the Hurricanes—the alternate band in the Kaiserkeller—and had deputised when Best was ill or unable to play, in Hamburg and Liverpool. Best's dismissal was reported by Harry on the front-page of the Mersey Beat magazine, upsetting many Beatles fans. The Beatles encountered some jeering and heckling in the street and on stage for weeks afterwards, with some fans shouting, "Pete forever, Ringo [Starr] never!" One agitated fan headbutted Harrison in The Cavern, giving him a black eye.
Reasons for dismissal
Best was never fully told why he was dismissed, as the only reason Epstein stated was, "The lads don't want you in the group anymore". Epstein subsequently claimed in his autobiography that Lennon, McCartney and Harrison thought Best "too conventional to be a Beatle, and though he was friendly with John, he was not liked by George and Paul". It has been documented (notably in Cynthia Lennon's book, John) that while Lennon, McCartney, and Harrison usually spent their offstage time together in Hamburg and Liverpool, writing songs or socialising, Best generally went off alone. This left Best on the outside, as he was not privy to many of the group's experiences, references, and in-jokes.
German photographer Astrid Kirchherr asked The Beatles if they would mind letting her take photographs of them in a photo session, which impressed them, as other groups only had snapshots that were taken by friends. The next morning Kirchherr took photographs in a municipal park called "der Dom" which was close to the Reeperbahn, and in the afternoon she took them all—minus Best, who decided not to go—to her mother's house in Altona. Best was described by Dot Rhone—McCartney's girlfriend at the time, who later visited Hamburg—as being very quiet, and never taking part in conversations with the group.